I don't think there has ever been a valid Pope. Not one. The only head of the Christian Church is Jesus Christ. He is the cornerstone. The title Pope is not mentioned in the Bible. Why would we need one? The Holy Spirit is available to all who earnestly seek help and guidance. Putting ones faith in man made denominations and pastors have led many to stray and fall away because of their shortcomings and sins.
Well, I agree but they think there have been so it’s relevant to them.
Then entire book of Acts is a history of the early church and Paul’s epistles address church leadership and there’s not a thing in it that supports Catholicism’s claims or practice.